<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>后代选择器</title>
    <style>
        .box p {
            color: red;
        }
    </style>
</head>

<body>
    <div class="box">
        <p>Text in .box</p>
    </div>
    <p>Text not in .box</p>
</body>

</html>